Brakes.. an idea !

During a good chat with thefolk at BookaTrack, I asked them what brakes they used on their track Elise… figuring whatever brakes work well for their hard-worked Elise is going to be ideal for my car.

They use Eliseparts bells/rotors… but their S2 car uses grooved discs, not drilled. (I remember reading that drilled discs can cause premature cracking etc…)

Looking at the Eliseparts site, it looks like the S1 discs are drilled/grooved whereas S2 are just grooved.

Would anyone else be interested in grooved only rotors for S1 Eliseparts bells ? If there was enough interest…

No (but thanks), they are way too thin. The Exige’s braking system benefits considerably from having the right thickness of disk.

AndyD (who’s on hols at the mo) recently compared a Eliseparts disk to an AP3000 one. Let’s just say, you get what you pay for.

Ian

Dave,
you can get the replacement rotors from Eliseparts or directly from Hi Spec (as they manufacture the disks and bells) grooved or flat.
I’ve tried this and although an improvement from the drilled/grooved, swiftly moved away from Hi Spec.

Wasn’t impressed with their quality either, sent them back because they juddered on first use and always hated that the casting was distorted (vanes moving side to side and thickness varying), but they just skimmed them and returned them. Still have them as a backup.

As Iain says, they’re too thin (gap very small), and therefore have a smaller inner cooling area. They just warp on heat and come back to shape as they cool(having said that, I’m heavy on the brakes).

Went for the MutsNuts but you can’t get them now. And of course I have to assume the AP’s are better (but expensive).

So, there you go, go for AP fronts and Eliseparts flat if you wish on the rear (as you need the bigger friction area to move the bias slightly rearwards, so less gaps)

LOL, well… it was a nice idea while it lasted

Eliseparts seem oblivious of anything wrong with their discs, claiming they send them all round the world.

Followup… got this back from Eliseparts:

“Yes I can offer just grooved discs but to be honest they are not great on anything over 200 bhp,I am developing some 295mm AP’s for the supercharged 300 bhp Hondas which will be ready in a few weeks (a more expensive though at �80 per disc & bell more but they will last 3 times as long).”

The eliseparts discs aren’t the best quality but they do the job. Geary and Simon are working on a better alternative though.

As some will know I have had some braking problems … pedal feeling fine to start and then “mushy” and air in the system … bleed and fine again … repeat …

What I found is this happens when the pads are worn halfway, on the Pagids you come accross some brass pins in the pad - I suspect that thats when to change them

Anyhow I also found my Eliseparts discs were well worn as well, didnt realise until I measured them …

Anyhow The total difference with worn discs and the original thickness against a new 25.4mm rotor is something like 4.5mm - so the pistons are now much further out, also its not equal so the inner piston is much further out than the outer and when the pads are worn clearly the piston is much further out …

What that adds up to I dont know but I dont like it, the brakes are still suburb on the road but on track I lost confidence in them … so I’m going to use 295 AP rotors with “Uldis” cooling on the front and 280mm AP rotors on the back.

Oh and They are grooved not drilled … I must admit I dont understand the statement that grooved are no good for over 200 HP

Andy

I still don’t think that worn pads/discs is the source of your mushiness…

I still feel that the mushiness must be coming from air/moisture in your system. In fact when you bleed it, the problem goes away, so how can the worn parts cause your problem ?

I think you have to try and find out how your getting air in… Do you use a pressure bleeder ? Is it a simple Eazibleed type device or a more sofisticated one that has a diaphram seperating the pressurised air from the brake fluid ?

Assuming you use a simple eazibleed device then its possible that you are ‘forcing air’ into your braking system when you bleed it !!! also you use SRF which will multiply the risk somewhat because its more hygroscopic that our mortal stuff. How about you try minimising the air pressure to the smallest value possible when you bleed the brakes and take utmost care NOT to get any air in there when you are doing it.
Anyway, I really hope you get to the bottom of it.

As some will know I have had some braking problems … pedal feeling fine to start and then “mushy” and air in the system … bleed and fine again … repeat …

What I found is this happens when the pads are worn halfway, on the Pagids you come accross some brass pins in the pad - I suspect that thats when to change them

Anyhow I also found my Eliseparts discs were well worn as well, didnt realise until I measured them …

Anyhow The total difference with worn discs and the original thickness against a new 25.4mm rotor is something like 4.5mm - so the pistons are now much further out, also its not equal so the inner piston is much further out than the outer and when the pads are worn clearly the piston is much further out …

What that adds up to I dont know but I dont like it, the brakes are still suburb on the road but on track I lost confidence in them … so I’m going to use 295 AP rotors with “Uldis” cooling on the front and 280mm AP rotors on the back.

Oh and They are grooved not drilled … I must admit I dont understand the statement that grooved are no good for over 200 HP

Have you tried new seals in the calipers?

Rox / Randy

Doh ! Should also have edited to say new caliper seals, and pistons actually … that was the real point about the problem …

Master cylinder?

Does sound like discs/pads, I ran my last set of Pagids very almost down to the metal and they remained great all the way through.

Rox / Randy

Doh ! Should also have edited to say new caliper seals, and pistons actually … that was the real point about the problem …

Andy

where did you get piston seals for the rears ?

still don’t think mushiness is a pad/disc wear issue in your case.

Randy

I’ve got a spare MC, keep thinking I should try it and never do - its bound to be that now I’m changing everything else

Rox - Your joking No chance - refurbs or new only …

Just to throw some fuel on the fire…

My brakes were getting very mushy with far less feel than before. I checked the pads and they were fine. Decided to bleed the brakes today with an Eezibleed. It’s been 3 years since I last bled them so I expected the fluid to look terrible. It didn’t… it looked fine. There were no air bubbles and it was nice and clear. Odd part is though, pedal feel is 10 times better now.

Moral: Just because your fluid looks ok and has no air in it, doesn’t mean it’s ok.

Bri

My brakes are pretty bad now. after 2500 km including 3 hard track days… Actually to my suprise 1 of my front wheels has no brake pad anymore so I have destoyed the disc (… So I need to change my brakes fast. wont be driving her before I have change them… Not quite sure which brakes to use??? But they must be good enough for a 300 bhp S1 Exige (might go for an upgrade next year)… So what should I use.??.. Was thinking of RS14 pads… and what about the " 4 pot Big brak conversion kit" from Eliseparts …any experience??? … and who offer the AP discs??? … As far as I can see I have the standard S1 Exige disc (280 mm)…

Some advice what to choose and where from is appreciated…

U can fit some Rs14s and if u have to change the discs get some 295 APs, find rotors and with small spacers on the caliper it should be ok.
Of course a 4 pot is nice but u have to spend more in time and money.

Nicolas